Caloneis nanyiensis sp. nov. SEM views of the external valve A, B external view of an entire valve note the raphe narrow and arched C details of the apices on the external valve; note the distal raphe fissures hooked and continuing on to the mantle D details of the striae on the external valve; note the Striae multiseriate, composed of small rounded areolae and areolae are occluded by heavy silicified, perforated hymenes E showing the central area. Scale bars: 5 µm (A, B); 2 µm (C, E); 1 µm (D).